On Wed, 2018-05-09 at 16:56 +1000, Nicholas Piggin wrote: > When a single-threaded process has a non-local mm_cpumask and requires > a full PID tlbie invalidation, use that as an opportunity to reset the > cpumask back to the current CPU we're running on. > > No other thread can concurrently switch to this mm, because it must > have had a reference on mm_users before it could use_mm. mm_users can > be asynchronously incremented e.g., by mmget_not_zero, but those users > must not be doing use_mm.
What do you mean ? I don't fully understand how this isn't racy with another thread being created, switching to that mm, and then having its bit cleared by us ? Also why not use_mm ? what prevents it ? Cheers, Ben.
